In most instances, OS2WWW is a plug-in replacement for Frankie Fan's OS2HTTPD server with performance improvements of typically 4.5 times faster response (350% better). The more heavily loaded the Web server, the better OS2WWW performs relative to OS2HTTPD. The dramatic speed improvement is achieved through careful optimisation of the original NCSA code and also extensive use of OS/2's multitasking capabilities.
After having been alerted to several compatibility problems, these have now been fixed - see the version history and the frequently asked questions (FAQ) for details.